Lecture Summary


Week 1- week 5

(Gums and stabilizers)


Hydrocolloid
  • Range of polysaccharides and protein
  • Also know as water soluble gums, stabilisers

Functions:
primary--->
  • Thickening agent
  • Gelling or texturizing agents
Secondary--->
  • Stabilisation of emulsion
  • Suspension of particulates
  • Control of cystallisation
  • Encapsulation

Structure of hydrocolloid

High degree of substitution, faster to hydrate
Low degree of substitution,slower to hydrate

High degree of polymerization,high viscosity-->slow to hydrate
Lower degree of polymerization,low viscosity-->faster to hydrate

Factors affect gum properties

  • Molecular weight
  • Monosaccharide composition
  • Type of side chain
  • Number of side chain
  • Distribution of side chain

List of hydrocolloid:
  • (Gelling Gums)

  • Pectin
  • Carrageenan
  • Alginate
  • Gelatin
  • Agar
  • Gellan
  • Konjac Glucomannan
  • Methyl cellulose ( hot)
  • (Thickening Gums)

  • Locust bean gum (LBG)
  • Tara gum
  • Gum Arabic
  • Gum karaya
  • Xantan gum
  • Guar gum
  • Tragacanth
  • Propylene glycol alginate
  • Carboxymethycellulose

Pectin


Raw material which are source of pectin:
citrus_peel.gifCitrus peel

Apple-Pomace.jpgApple pomace

images.jpgSugar beet chips

Natural form is called protopectin ( where they are still in primary form and not yet extracted)

Types of pectin
High methoxyl pectin (HMP)---> degree of esterification>50%
Low methoxyl pectin (LMP)--->degree of esterification<50%
DE=Galacturonic acid partially esterified as methyl esters.

HMP
  • To form gel, the soluble solid content must be 5-58% and PH 2.8-3.8 in jam and jellies.
  • its a rapid set(DE 77) & slow set(DE 58)
  • Rapid set- widely used in jams with whole fruits(marmalade) -->to ensure uniform distribution
  • Acidic fruit( blackcurrant) require slow set---> avoid premature gelation
  • Not heat reversible
  • Gels at high temperature and low PH
  • DE high, ability to gel high

LMP
  • 2 sub groups, conventional LMP, and Amidated LMP.
  • Calcium ion needed for it to form gel with low solid content and PH 1-7.
  • Thickening agent in yoghurt-because less calcium ion reactive than ALMP
  • Assist gelation in low sugar jam and jellies-because very reactive calcium ion
  • Heat reversible

Usage of pectin in food

  • Jams, jellies and preservatives
  • Stabilisers( in fruit juices, fruit drinks concentrated)
  • In fermented/directly acidified dairy products
  • Used in baked products-cake glazing,fruit fillings (confectioneries)
  • Soft drinks and sherbets
  • Ketchup,sauces,and chutneys


Carrageenan

Extracted of red algae, the Carrageenan structure composed of linear galactan polysaccharides that have sulfate(negative charge).

3 types---> kappa , Lambda, and Iota

  • Kappa and Iota Carrageenan have ability to form thermoreversible gels upon cooling of hot aqueous solution contain cation example potassium ion.
  • Lambda does not form gel



(Carrageenan versatile as food additives, because they are capable of binding water,promoting gel formation, act as thickener and stabilizing agents as well as improve the palatibility and food's appearance)

Food examples that use carrageenan

1219654793.jpg Buy_Carrageenan_For_Jelly_Dessert.jpg


Desserts, gels, ice-cream, chocolate, milk, canned foods.